Sunshine on my solar panels makes me happy. Photos: Daniel Shaw In and around Aspen, Colo., incorporating green into the building process usually means wondering, "How much cash can I spend on my house?" After all, this valley sports some of the most energy-sucking but least-used second, third, and fourth homes on Earth. One of them, former Saudi Ambassador Prince Bandar Bin Sultan's 55,000-square-footer, can be yours for $135 million. What are the utility bills? Who the hell cares! Spec homes topping 15,000 square feet are still popping up without a solar panel in sight in a place where the …